There are several hundred million users of wireless mobile devices, including cellular telephones, in the world today. Competition, improved technology, and the building of a large wireless infrastructure have made wireless service widely available, while driving the price of wireless service down to the point where it is affordable to a large segment of the world population.
The previous generation of cellular phones were used primarily for voice conversations between a subscriber using a wireless mobile station (i.e., a cell phone) and another party. Increasingly, however, wireless mobile stations are data processing devices, such as personal digital assistant (PDA) systems equipped with cellular/wireless modems. These wireless PDA systems include a variety of handheld computers made by Palm, Inc., Compaq Corporation, Handspring, Inc., and others. The wireless PDA systems are used for web-browser applications, e-mail applications, remote network access, interactive games, and the like. More recently, wireless mobile stations have been introduced into the marketplace that are combination devices that operate both as a cell phone and as a data processing device.
The widespread use of wireless mobile devices has not been without its drawbacks, however. Many environments are not suitable for the use of wireless mobile stations. For example, there has been a great deal of concern that wireless mobile stations, primarily cell phones, may interfere with the avionic systems on aircraft. This has lead to a ban on the use of cell phones and other wireless mobile devices (e.g. Palm VII™) on aircraft. Cell phones also have been banned in movie theaters, symphony halls, hospitals, and similar places where the ringing of a cell phone may be a distraction or annoyance.
However, many wireless mobile stations also operate in a stand-alone mode in which an application that does not require a wireless capability may be executed. For example, a passenger on an airplane may wish to play a video game on a cell phone or may wish to view his or her appointment calendar when running a personal organizer application on a wireless PDA. The passenger cannot do this, however, if the use of cell phones or wireless PDA devices is prohibited on the plane. Many cell phones and other wireless PDA devices automatically try to establish radio frequency (RF) connections as soon as the devices are turned ON. This is true even if the users do not require RF connections. In attempting to access a local wireless network, these devices transmit RF signals, even if there is no wireless network in the area. In other wireless PDA devices, an RF connection is not automatically established when the device is turned ON, but only in response to a user command. However, there is no way for a flight crew member or a theater operator to simply glance at such a wireless PDA in order to determine that the PDA device is not transmitting or receiving RF signals. The end result is that a total ban on wireless mobile stations of all varieties is generally enforced, without regard to whether or not the wireless mobile stations are transmitting RF power.
Therefore, there is a need for a wireless mobile station in which RF power may be disabled in a highly visible and unambiguous manner so that applications that do not require an RF connection may be executed on the wireless mobile station.